Figure 7.

(a) Durability test under the pressure of 0–300 Pa, (b) stability and (c) hysteresis test of the sensor, (d) transient response to the application and removal of a 24-mg-weight rice seed on the sensor, the corresponding pressure is 1 Pa, (e) SEM image of the pyramid microstructures after pressure tests, indicating the robustness of the metal coating under pressure. (f) and (g) are the detailed image of the Ti/Au-coated PDMS tip after pressure tests, the square stains are generated under different pressures, (h) real-time detection of the wrist pulse signal.